fix: After clearing merchant and saving it, Merchant field reverts to previous value Expensify#63587

Author: ganzz4

src/libs/TransactionUtils/index.ts

@@ -677,6 +677,15 @@ function getMerchant(transaction: OnyxInputOrEntry<Transaction>, policyParam: On
             toLocaleDigit(TranslationStore.getCurrentLocale(), digit),
         );
     }
+
+    // Check if this is a workspace expense transaction
+    const report = getReportOrDraftReport(transaction?.reportID);
+    const isWorkspaceExpense = report?.type === CONST.REPORT.TYPE.EXPENSE;
+
+    // Allow empty merchant only for personal expenses, not workspace ones
+    if (transaction?.modifiedMerchant === '' && !isWorkspaceExpense) {
+        return '';
+    }
     return transaction?.modifiedMerchant ? transaction.modifiedMerchant : (transaction?.merchant ?? '');
 }
 

src/pages/iou/request/step/IOURequestStepMerchant.tsx

@@ -100,10 +100,13 @@ function IOURequestStepMerchant({
             navigateBack();
             return;
         }
-        // When creating/editing an expense, newMerchant can be blank so we fall back on PARTIAL_TRANSACTION_MERCHANT
-        setMoneyRequestMerchant(transactionID, newMerchant || CONST.TRANSACTION.PARTIAL_TRANSACTION_MERCHANT, !isEditing);
+
+        // Fallback to PARTIAL_TRANSACTION_MERCHANT only if merchant is null or undefined
+        const merchantValue = newMerchant ?? CONST.TRANSACTION.PARTIAL_TRANSACTION_MERCHANT;
+
+        setMoneyRequestMerchant(transactionID, merchantValue, !isEditing);
         if (isEditing) {
-            updateMoneyRequestMerchant(transactionID, reportID, newMerchant || CONST.TRANSACTION.PARTIAL_TRANSACTION_MERCHANT, policy, policyTags, policyCategories);
+            updateMoneyRequestMerchant(transactionID, reportID, merchantValue, policy, policyTags, policyCategories);
         }
         navigateBack();
     };